ok i have an 04 s.d. 5.4 truck. i have the activatorII brake controller, wired to the adapter for the ford trucks with the wires connected correctly.
Mr problem is that when i hook the trailer up, and set it up how the insstructions say. the brakes lock up violently and it seems like the brakes never release, even on 0.0
First i went over everything, from the shoe adjustment to the trailer wiring the grounds the truck side and so on.

i found that even when i have no brake application and the the key is out of the ignition and in my pocket, there is 12.6 volts at the blue brake control feed at my 7-way on the bumper. when you step on the brake surprisingly it goes down to 11.8 volts. this is with the trailer disconnected.
and yes ive tried two more brake controller boxes and got the same results

this makes me believe that this would be why the trailer brakes are dragging?

anyone ever have this problem or come across this before?

 

Is this a new install or has it been in there for a while and just started doing this ?

 

its been doing it for a while. i swapped out my axle in my trailer for one with brakes wired it all up matched everything at the plugs. the trailer works fine on my friends chevy and my other friends ford E van that has the trailer brake controller wired like it shows in the instructions, not with the adapter harness.
it is nothing mechanical iave had the drums off and checked everything, the adjument it set fine. like i said the plug at the back of the truck has power all the time at the brake controll feed to trailer. when you stop the truck its like its got a parking brake on the trailer holds you back.
i thought it might of been a ground issue like the electro magnet wont un magnetize like the ground was bad. but it is just plain not releasing due to havin power all the time.

i know according to the Activator II trouble guide, it is supposed to have half battery voltage at the vehicle side plug with the trailer unplugged and no foot on the brake, with a controller connected of course. but like i said im getting 12.6 not 6.3

 

first off you should not have any voltage at the vehicle side plug when the controler is not activated. Have you tried unpluging the controler under the dash and see if there is still power to the rear plug ? If so then you have a short somewhere that is feeding the blue wire. Did you do any rewiring in the back of the vehicle recently ?

 

yes ive tried everything, except running my own wire.

no one has touched the truck, ever. its only got 20k on it and ive had it since 8k previous owner was a friend who did nothing but 3 oil changes before i got the truck.

Ive had issues with other fords using factory wiring and it not working. where i would have to make my own leads, or even run my own complete wiring for the brake controller.

Has anyone had this issue

 

You havent changed out the plug on the back of the truck ever ?

 

ok i swear when i say NOTHING has been touched truck side i mean NOTHING. if you use a test light/DVOM to check the plug everything is right where its supposed to be left turn right turn park lights 12v ground back up lights and trailer brake output. if you put in one of those 7way testers all the lights do what they're supposed to but you notice, that the brake out put light is dim and if you use the contorller to add power it will get brighter and lighter with the roll of the reostat.

 

Ok now I am confused you said in your OP that you had 12 volts at the blue wire on the plug that would mean brake control max output now you say blue wire power ramps up and down by cycling the controler

 

this is not true for most brake controllers.

Many brake controllers send out a feeler signal to see if there is a trailer attached. This will show up as a voltage when tested, but if you try to put a load on it, you will quickly find out what a "pull-up resistor" does.

 

Bigpipes 35:
i mentioned that when you use one of the plug in 7way testers the little bulb is lit up and when you run the reostat up and down with the manual button or foot on the pedal you can see the light go from dim to full bright.
when i use a voltmeter at the terminal. i get 12.6 key off and 11.8 key on and when you apply the brake nothing changes. this is with trailer disconnected.


TexasRebel:
that was just a feeling of my that there shouldnt be any voltage going to the magnet cause that would cause it to drag, and like i stated above i know it is supposed to have hlaf battery voltage with the controller connected and no trailer plugged into the socket at the back of the truck, i know this because this is not the first truck/trailer ive ever wired. yes i know there is some voltage so there is no so much take up when the brakes are applied and to create slight drag but this is no slight drag it holds the trailer and truck back.

 

no, when the brakes are connected, the pull-up resistor does it's job. Current (in the micro-amp range) flows across the pull-up resistor and the magnets just to tell the brake controller that something is connected to it. This doesn't apply the brakes at all.

The voltage in the feeler circuit will either be a full 12.6v, 5v, or 3.3v depending on the controller and which microprocessor and voltage regulator the designer spec'ed out.

 

YES! i now agree with texasrebel.

i made a bench top model witha brake controller to figure out how the wiring really works. yes with the activatorII controller and no trailer at the rear socket on the truck you will get full battery voltage.

so its not the truck side!

i have a TOWDOCTOR trailer tester, so i went to the trailer to test.

had trailer on the lift and if you spun the wheel and hit the brake activation on the towdoctor. the wheels would violently lock up and then not release. unless you went the opposite direction.

So stripped the wheels and drums off the trailer, i inspect the shoes, and springs and magnets again. i everything seemed to be normal. the movement or the servo arm that the magnet is on seemed to be a little sticky.

So i stripped everything down cleaned it all up and upon reassembly i used the cooper paste high heat lubricant where the shoes make friction with the backing plate. the joint where the servo arm attaches tot he baking plate. every spot where there was contact. Just like you would on a normal automotive drum brake replacement. adjusted them up and what do you know.

THEY WORK!

They we unable to release because the servo arm was binding up and jamming the pads.

This is what i get for buying a brand new axle assembled with the brakes no it already, and just thinking, oh hey if the manufacturer put it together it should be right........ yeah, right!

Moral of the story lube your parts! and double check everyone elses work!